This invention pertains to an antenna system. More particularly, this invention relates to an antenna system with antenna orientation adjustment. This invention also pertains to an associated method for optimizing antenna operation.
It is well known that antennas have a marked directional character, that is, antenna reception sensitivity varies in accordance with signal frequency and antenna orientation relative to the source of the broadcast signal. Similarly, signal strength for a transmitting antenna varies as a function of signal frequency and signal angle about a transmission axis of the antenna. The patterns of signal strength (transmission) or sensitivity (reception) have a generally lobed configuration, i.e., a configuration with lows alternating with highs about the transmission or reception axis of the antenna.
Indoor television antennas such as so-called rabbit ears, are generally manipulated by hand to maximize or optimize reception. Outdoors antennas are generally stationary. Consequently, for outside antennas, reception for the various channels is fixed on installation. Reception is optimized only by matching as best as possible the structure and fixed orientation of the outdoors antenna to the directions of incoming broadcast signals.
Attempts have been made to modify the impedance of an antenna circuit in order to improve signal quality. These attempts have met with limited success. Improvements in signal quality are best attained by maximizing the strength of the received signal.
It is known to automatically adjust the position of an indoor antenna in response to a wireless channel selection signal. A reversible motor is connected to the antenna. The direction of rotor rotation of the motor is reversed each time the motor is energized in response to a wireless channel selection signal. Thus, the indoors antenna is rotated in one direction when a user first activates a remote control unit to change the channel displayed on a television receiver. Subsequently, after the antenna has rotated past an optimal position, the user releases the channel selection button of the remote control unit and again pushes the same button to reverse the rotation of the antenna. The user releases the selected channel selection button when the antenna reaches its optimal orientation for the selected channel.